Technical Field
The present disclosure relates to a photographing optical lens assembly. More particularly, the present disclosure relates to a compact photographing optical lens assembly applicable to electronic devices.
Description of Related Art
In recent years, with the popularity of electronic devices having camera functionalities, the demand of miniaturized optical systems has been increasing. The sensor of a conventional optical system is typically a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor. As the advanced semiconductor manufacturing technologies have allowed the pixel size of sensors to be reduced and compact optical systems have gradually evolved toward the field of higher megapixels, there is an increasing demand for compact optical systems featuring better image quality.
A conventional optical system employed in a portable electronic product mainly adopts a three-element lens structure or a four-element lens structure. Due to the popularity of mobile terminals with high-end specifications, such as smart phones, tablet personal computers and wearable apparatus, the requirements for high resolution image quality of present compact optical systems increase significantly. However, the conventional optical systems cannot satisfy these requirements of the compact optical systems.
Other conventional compact optical systems with five-element lens structure are disclosed. However, the refractive power and the surface shape of the lens elements are not favorable for forming a telephoto structure and providing the first lens element (which is the lens element closet to an object side of the optical system) with sufficient light converging ability. Furthermore, the focal lengths of the lens elements and axial distances between the lens elements are not favorable for providing sufficient space for controlling optical paths of the light rays entering into the optical system while controlling the refractive power of the first lens element. As a result, a long-shot scene cannot be clearly imaged on an image surface of the optical system, and the image quality is poor.